A miniaturized method for HPLC-MS/MS identification of wine markers in figured pottery

Abstract

The study of Organic Residue Analysis (ORA) in archaeological pottery aims to detect traces of organic materials, such as food and beverages, that were once contained in the vessels. Chemical analysis of organic residues can confirm hypotheses made by archaeologists regarding some important aspects of ancient daily life, from ancient diet to rituals. If non-invasive analytical techniques, such as spectroscopies, could provide issues with overinterpretation of the data, chromatographic techniques combined with various detectors may be more suitable for separating and identifying the different components within a complex matrix, like archaeological pottery. This research aims to develop a new rapid, reproducible and efficient method for the identification of organic acids as wine markers in archaeological figured vessels through HPLC-MS/MS. The procedure included a derivatization step and an extraction step, both designed based on green analytical chemistry principles. It employed ultrasound-assisted liquid extraction and dispersive liquid-liquid microextraction (dLLME). dLLME allowed to remove compounds that induce signal suppression, thereby minimizing the matrix effect. Except for tartaric acid, which had a recovery around 20 %, the other analytes had recoveries that ranged from 40 % to 60 %, while LODs were comprised between 0.01 and 0.05 ng mL⁻¹. This method was applied to examine the potential presence of wine in figural pottery, validating the method on historical samples in the frame of the wide-scope project Imag-ORA.